Happy Moves, Sad Grooves: Using Theories of Biological Motion and Affect to Design Shape-Changing Interfaces
The design of shape-changing interfaces to show emotions relies on craft skill with few clear guidelines. Through two experiments, we explore how to design such interfaces using theories of the relation between biological motion and affect. In the first experiment, 19 participants viewed six shape-changing behaviors that varied the velocity, fluidity, direction, and orientation of the movement of an extrusion from a small box in accordance with existing theories of affective motion. Participants were able to recognize four of the six intended basic Ekman emotions (sadness, fear, happiness, surprise) with above-chance probability. The second experiment used 36 shape-changing behaviors that systematically varied speed, regularity of motion, and direction. For each behavior, 23 participants rated valence, arousal, and dominance. Speed, direction, and orientation impacted emotion ratings significantly and in the predicted directions. These results offer an initial basis for the systematic design of emotions in shape-changing interfaces.